Matúš Hyžný

Fossil and modern fiddler crabs (Uca tangeri: Ocypodidae) and their burrows from SW Spain: ichnologic and biogeographic implications

The burrowing activity of the only European fiddler crab species, Uca tangeri (Eydoux, 1835), was studied along the shores of the estuary of the Piedra River in Lepe, southwestern Spain. Casting of burrows allowed recognition of their simple, J-shaped to irregular architecture, which displays striking similarities to fossil Pliocene burrows in the same area. The finding of body fossils of U. tangeri in contemporaneous strata indicates these trace fossils are produced by the same species and demonstrate its presence in the eastern Atlantic coast at least for the last three million years. Burrows of U. tangeri are similar to those of other Uca spp. worldwide and also to those of other brachyurans. Their architectural simplicity makes difficult their definitive recognition in the fossil record. Nevertheless, review of existing literature confirms the presence of brachyuran burrows at least since the Cretaceous.

Decapod crustaceans from the Cretaceous (Aptian–Albian) San Gil Group in the Villa de Leyva section, central Colombia

Abundant concretions at two localities in central Colombia where the San Gil Inferior and San Gil Superior formations are exposed, have yielded numerous crustacean individuals, comprising one new genus Rathbunassa n. gen. (Callianassidae), two new species Joeranina colombiana n. sp., Planocarcinus johnjagti n. sp., and three further species. The following taxa are recorded: ?Paraxiopsis sp. (Axiidae), Rathbunassa aquilae (rAtHBun, 1935) n. comb. (Callianassidae), Joeranina kerri (Luque, FeLdmAnn, SCHweitzer, JArAmiLLo & CAmeron, 2012) n. comb., Joeranina colombiana n. sp. (Palaeocorystidae), Cenomanocarcinus vanstraeleni StenzeL, 1945 (Cenomanocarcinidae), and Planocarcinus johnjagti n. sp. (Necrocarcinidae). Based on ammonite evidence, the locality within the San Gil Inferior Formation is considered to be of late Aptian age, while the one exposing the San Gil Superior Formation is of middle Albian date. Joeranina kerri is found at both localities; in contrast Planocarcinus johnjagti n. sp. occurs exclusively in the upper Aptian, while the remainder of species are all from the middle Albian locality. The taxa reported herein add important data to the palaeobiodiversity and distribution of Cretaceous decapod crustaceans.

Growth, inter- and intraspecific variation, palaeobiogeography, taphonomy and systematics of the Cenozoic ghost shrimp Glypturus

Studies in systematic palaeontology are greatly aided when numerous, well-preserved specimens are available so that quantitative methods can be used to substantiate qualitative observations. This is often not the case for fossil decapod crustaceans due to their relatively low preservation potential. Here, we examined primarily two large collections of the well-preserved ghost shrimp Glypturus from the Holo-Pleistocene of Panama and the late Miocene of Florida. Using descriptive, bivariate, multivariate and geometric morphometric methods, two new species are described based on appendage material: Glypturus panamacanalensis sp. nov. and G. sikesi sp. nov. New characters are identified, and size-related and intraspecific variation are assessed for these taxa and modern G. acanthochirus. Taxonomic placement of single specimens from other localities was confirmed by multivariate methods. Furthermore, Glypturus is revised, especially with regard to Western Atlantic species that inhabited both carbonate and siliciclastic environments. Callianassa anguillensis, C. latidigata, and Neocallichirus? quisquellanus are referred to as Glypturus sp. until more material is available to determine the validity of these species. Diversity within Glypturus may thus be underestimated, thereby also impacting the assessment of phylogenetic relationships. Minor propodi appear under-represented relative to major propodi, suggesting a taphonomic bias. Single specimens of interest include a specimen of G. panamacanalensis sp. nov. exhibiting a peculiar swelling in the fixed finger and another showing damage on the propodal upper margin, suggesting failed predation or antagonistic behaviour. Glypturus is first found in the Oligocene in the Western Atlantic and may have expanded its palaeobiogeographical range since the Miocene. The genus was still present on the Pacific side of the Isthmus of Panama in the Holo-Pleistocene, but is only known from the Western Atlantic today, suggesting a relatively recent extinction on the Pacific side. http://zoobank.org/urn:lsid:zoobank.org:pub:C7F0C071-F2AD-4684-B277-037B6F91BF0E

Deep-water fossorial shrimps from the Oligocene Kiscell Clay of Hungary: Taxonomy and palaeoecology.

We describe deep-water ghost shrimp assemblages from the otherwise well known Oligocene Kiscell Clay in Hungary. The described fossorial shrimps (Decapoda: Callianassidae and Ctenochelidae) include: Ctenocheles rupeliensis (younger synonym Callianassa nuda) and Lepidophthalmus crateriferus (younger synonym Callianassa brevimanus). The fossil material of the former species is assigned to Ctenocheles based on the morphology of the major cheliped, particularly the pectinate fingers, bulbous propodus, cup-shaped carpus and elongated merus. Lepidophthalmus crateriferus from the Oligocene of Hungary is the first unequivocal fossil record of the genus, which is distinguished in the fossil record on the basis of the presence of a meral blade and meral hook on the major cheliped. Lepidophthalmus is today known exclusively from shallow-water environments. The finding of a deep-water fossil representative of Lepidophthalmus therefore appears to be a reverse of the common pattern of groups shifting environments from onshore to offshore over geological time, as seen in many taxa. The presence of Lepidophthalmus crateriferus comb. nov. in the Kiscell Clay therefore suggests different ecological requirements for at least some populations of this genus in the geological past.

Podocallichirus laepaensis, a New Ghost Shrimp (Crustacea, Decapoda, Callianassidae) from the Late Miocene of Southwest Spain

Abstract Callianassids are among the most commonly found decapod crustacean fossils but their generic assignment is often difficult. Numerous cheliped remains have been found in the upper Miocene deposits of southwest Spain allowing description of a new species of a ghost shrimp, Podocallichirus laepaensis. The assignment of the new form to the respective genus is based mainly on the morphology of the major cheliped merus and provides useful implications for paleontological studies. Podocallichirus laepaensis is the first fossil record of the genus known to date. Several specimens preserved in association with and within Ophiomorpha traces are interpreted as in situ preservation. Thus, the new ghost shrimp is identified as the producer of trace fossils.

The fossil record of Glypturus (Decapoda: Axiidea: Callianassidae) revisited with additional observations and description of a new species

The extent of propodal tuberculation is considered taxonomically important for species of the callianassid genus Glypturus (Decapoda: Axiidea). Based on cheliped material from the Middle-Late Miocene of Iran, Glypturuspersicus n. sp. is described here. It possesses no tuberculation on the outer surface of the major propodus, whereas its inner surface is moderately to heavily tuberculated in terms of its extent. It resembles extant Glypturus armatus, but this species is completely smooth on both propodal surfaces. A reappraisal of Glypturus toulai from the Early and Late Miocene of Panama is presented. Additionally, the type material of Glypturus fraasi from the Late Eocene of Egypt is figured. In the nature of tuberculation, an evolutionary trend is observable in Glypturus with the most tuberculated forms from the Palaeogene and less tuberculated forms from the Neogene. This trend is clearly seen in the possible West Atlantic lineage of the genus.

Revision of Jaxea kuemeli Bachmayer, 1954 (Decapoda: Gebiidea: Laomediidae) from the Miocene of Europe, with remarks on the palaeobiogeography of the genus Jaxea Nardo, 1847

The present contribution reevaluates the fossil record of the genus Jaxea (Decapoda: Ge-biidea: Laomediidae) and gives an emended diagnosis and an updated description of Jaxea kuemeli based on well preserved material from the lower and middle Miocene strata of Austria, Slovakia and Hungary. The species is distinguished from the extant J. nocturna on the basis of the tooth formula of the chelipeds. The geographic distribution and the palaeobiogeography of the genus is discussed and migration from the Tethys eastward towards the present-day Indo-Pacific Ocean during the Miocene time is proposed. The fossil record of the family Laomediidae is shortly reviewed. The monotypical genus Reschia from the Tithonian of southern Germany once tentatively assigned to Laomediidae is excluded from the family.

168 million years old “marine lice” and the evolution of parasitism within isopods

BackgroundIsopods (woodlice, slaters and their relatives) are common crustaceans and abundant in numerous habitats. They employ a variety of lifestyles including free-living scavengers and predators but also obligate parasites. This modern-day variability of lifestyles is not reflected in isopod fossils so far, mostly as the life habits of many fossil isopods are still unclear. A rather common group of fossil isopods is Urda (190-100 million years). Although some of the specimens of different species of Urda are considered well preserved, crucial characters for the interpretation of their lifestyle (and also of their phylogenetic position), have so far not been accessible.ResultsUsing up-to-date imaging methods, we here present morphological details of the mouthparts and the thoracopods of 168 million years old specimens of Urda rostrata. Mouthparts are of a sucking-piercing-type morphology, similar to the mouthparts of representatives of ectoparasitic isopods in groups such as Aegidae or Cymothoidae. The thoracopods bear strong, curved dactyli most likely for attaching to a host. Therefore, mouthpart and thoracopod morphology indicate a parasitic lifestyle of Urda rostrata. Based on morphological details, Urda seems deeply nested within the parasitic isopods of the group Cymothoida.ConclusionsSimilarities to Aegidae and Cymothoidae are interpreted as ancestral characters; Urda is more closely related to Gnathiidae, which is therefore also interpreted as an ingroup of Cymothoida. With this position Urda provides crucial information for our understanding of the evolution of parasitism within isopods. Finally, the specimens reported herein represent the oldest parasitic isopods known to date.

An appraisal of Typilobus Stoliczka, 1871 (Crustacea, Brachyura, Leucosioidea), with description of a new family and genus

Since its description, Typilobus Stoliczka, 1871, has become something like a catch-all taxon to accommodate fossil leucosioid crabs with uncertain affinities. As many as 17 species have been assigned to Typilobus, recorded from the Eocene to Miocene strata of Europe, Africa, and Asia. The re-examination of the type species, Typilobus granulosus Stoliczka, 1871, from the Miocene of Pakistan, has shown inconsistency in its description and published figures leading to the need of a revision of all species assigned to Typilobus. Typilobus boscoi Vía Boada, 1959, from the Middle Eocene of Spain, is revised and assigned to Folguerolesia n. gen. Characters present on ventral portions of male and female specimens differ from all known representatives of Leucosioidea, although the general morphology supports inclusion in this superfamily. A new family, Folguerolesiidae n. fam. is thus erected to accommodate Folguerolesia boscoi comb. nov., leading to recognition of three families of leucosioid crabs, including Iphiculidae and Leucosiidae.

Ghost shrimp Calliax de Saint Laurent, 1973 (Decapoda: Axiidea: Callianassidae) in the fossil record: systematics, palaeoecology and palaeobiogeography

Ghost shrimps of the family Callianassidae are very common in the fossil record, but mostly as isolated cheliped elements only. The assignment to biologically defined genera, diagnosed on the basis of soft part morphology, is thus rather difficult. In this respect, proxy characters present on chelipeds that are the most durable ghost shrimp remains are needed to ascribe fossil material to extant genera. The genus Calliax de Saint Laurent, 1973 has been particularly obscure in this respect. Thorough comparison of extant members of the genus resulted in evaluation of characters present on chelipeds being taxonomically important on the genus level, specifically: 1) rectangular major P1 propodus with two ridges on the base of the fixed finger extending onto manus; 2) major P1 fingers relatively short; and 3) minor P1 chela with dactylus longer than fixed finger and possessing a wide gap between fingers. On this basis, Callianassa michelottii A. Milne Edwards, 1860, from the Oligocene and Miocene of Europe is herein reassigned to Calliax. Further re-examination of the ghost shrimp fossil record revealed that C. szobensis Müller, 1984, from the Middle Miocene of Hungary represents the same animal as C. michelottii and they are synomymised herein. The known geographic distribution of C. michelottii is expanded by the first confirmed occurrence of the species in Slovakia. All occurrences of C. michelottii known to date are reviewed and documented. The presence of Calliax michelottii comb. nov. may be considered an indicator of deeper marine settings. Based on the scarce fossil record known to date, Calliax has a Tethyan origin; it supposedly migrated westward to establish present day communities in the Caribbean sometime before the Middle Miocene.